Electrochemically Induced pH Change: Time-Resolved Confocal Fluorescence Microscopy Measurements and Comparison with...

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Optical Microscopy

Background:

• Confocal fluorescence microscopy is established for imaging near-electrode pH.
• Understanding electrode processes requires time-resolved pH measurements, a capability previously lacking.
• Dynamic pH changes are crucial for analyzing electrochemical reactions.

Purpose of the Study:

• To present the first time-resolved pH profiles using confocal fluorescence microscopy.
• To validate the technique against theoretical models and identify limitations.
• To explore buffer effects in electrochemical systems.

Main Methods:

• Utilized confocal fluorescence microscopy for time-resolved pH measurements.
• Developed and employed a one-dimensional reaction-diffusion model for comparison.
• Investigated factors influencing pH measurement accuracy, including light attenuation and dye migration.

Main Results:

• Successfully achieved time-resolved pH profiling with confocal fluorescence microscopy.
• Experimental data aligned with the reaction-diffusion model until three-dimensional effects emerged.
• Demonstrated the method's ability to reveal buffer effects in sulfate electrolytes.

Conclusions:

• Confocal fluorescence microscopy can now provide 3D time-resolved pH measurements in electrochemical settings.
• The technique offers a powerful new tool for studying dynamic electrochemical interfaces.
• Future applications include analyzing phenomena like bubble formation at electrodes.